This invention relates to automatic embroidery machines. More particularly it relates to a system and method for improving the adjustments of automatic embroidery machines to manufacture an improved embroidered article.
Many years ago embroidery machine frames were adjusted by hand for each stitch change in the embroidered article. The advent of automatically controlled embroidery machines was a significant advance in the art both in frame movement speed and in the large number of articles which may be simultaneously embroidered. Normally these machines are controlled by an elongated tape, sometimes referred to as a Jacquard tape, having holes punched therein. The holes contain the stitch length, direction and function information which is read by an optical reader. The information is converted to electrical pulses and fed to a stepper motor which is, in turn, coupled to a torque amplifier to cause the large embroidery frame to move. The stepper motor and torque amplifier are referred to as the frame drive system.
In the past the resolution or distance increment movement of the frame drive system has been a bottleneck in providing embroidered articles of very fine stitch resolution. In one system known as the Vomag system the stitch resolution has been 1/6 mm. and in another system called the Saurer system the resolution has been 1/10 mm. The Vomag system is also sometimes referred to as the Plauener or Zahn system. With the advent of improved drive systems, including better stepper motors, there is a possibility of great improvement in stitch resolution. Finer resolution would greatly improve the quality of embroidered articles.
A major limiting factor in improving the resolution would be the requirement to use new technology such as magnetic disks, 8-channel tapes and other means which would require the abandonment of all existing Jacquard tapes and their respective patterns, or building special equipment to convert existing tapes to a new format. This would involve large investments in additional equipment, high costs of producing conversions and costly delays in production while awaiting for conversion.
Jacquard tapes, such as the one illustrated in FIG. 1, have been provided for programming the above-mentioned lower resolution systems. The system which is illustrated in FIG. 1 happens to show the Vomag system, which is adapted to provide 1/6 mm. resolution for stitches. Another system which also utilizes Jacquard tapes is the so-called Saurer system, which provides for 1/10 mm. resolution. However, for simplicity sake the Saurer system will not be further described in detail, although the principles are basically the same.
The Vomag system utilizes a plurality of rows 10, each of which is divided into a left side 12 and a right side 14, each of which has 18 spaces. The left side controls the vertical frame movement and the right side controls the horizontal frame movement. The direction of the frame movement along the X axis and Y axis is controlled by outer function holes 16. Other outer holes control certain other functions of the embroidery machine.
In order to indicate stitch length and angular direction either 0, 1 or 2 holes are punched in each line 12 and 14. The spaces on each line are weighted, and count 1 to 10 from the center out with each number indicating the movement of 1/16 mm. The remaining spaces represent the numbers 10 to 90 in ascending units of 10. Therefore, if holes appeared in the space 70 and the space 4, the resulting number would be 74 and the machine would then move 74/6 mm. on the vertical axis. If the horizontal axis holes indicated 23, the machine would move 23/6 mm. horizontally. The resultant vector of combining 74/6 mm. and 23/6 mm. would yield the angular direction and length of stitch. The existence of or lack of hole spaces 16 in the margin determine whether or not you go in the plus or minus direction for each axis.
The width of the tape, the distance between adjacent rows and adjacent spaces for receiving hole punchings are fixed for tapes encoded using the Vomag system so that machines that do the hole punchings as well as readers may be standarized. The same is true for tape encoded under the Saurer system.
These prior art systems have served the embroidery industry well and have been acceptable where stitch resolution is limited to 1/6 or 1/10 mm. because of limitations in the prior art drive systems and frame movement devices. However, with the advent of drive systems which are capable of providing improved resolutions, the Vomag and Saurer systems are not able to handle improved resolutions. For example, in the Vomag system there are only 99 possible frame movement increments for each axis. In a high stitch resolution such as a 1/30 mm. the longest stitch length would be 99/30 mm. which is unacceptable. Therefore, there exists a need to provide a new tape reading system which utilizes the higher resolution drive system which is still compatible with the prior art tape system.